In the manufacture of MWIR narrow band emitters, it was heretofore the practice to etch holes in a substrate and heat the substrate from behind. The resulting structure would act as a filter allowing only a narrow window of the IR radiation through. There was no gain in efficiency and the tolerances in manufacturing were not easy to achieve. In addition the previous method and structure used gold. The emissivity of gold is very low, also adding to the low power efficiency.
There is, therefore, a need for a more efficient process for manufacturing MWIR narrow band emitters. In particular, there is a need to integrate the additive tungsten CVD process of the present invention allows for better control of the device parameters.